Cooling systems and methods

ABSTRACT

A method of operating a cooling system that has at least one evaporator containing a refrigerant and at least one adsorbent chamber containing adsorbent configured to provide adsorption of vaporized refrigerant from the at least one evaporator in a cooling mode and provide desorption of the refrigerant to the at least one evaporator in a recharging mode, the method including; controlling the adsorption and desorption of the refrigerant of the at least one adsorbent chamber between the cooling modes and recharging modes during a cooling cycle; ceasing desorption of the refrigerant from the at least one adsorbent chamber; allowing adsorption of the vaporized refrigerant from the at least one evaporator; and maintaining the at least one adsorbent chamber in an adsorbed state at the end of the cooling cycle in a storage mode.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/681,526 filed Apr. 8, 2015, entitled “Cooling Systems and Methods”,which is a continuation of U.S. patent application Ser. No. 14/204,920filed Mar. 11, 2014, entitled “Cooling Systems and Methods”, whichclaims the benefit of U.S. Provisional Patent Application No. 61/788,574filed Mar. 15, 2013 entitled “Cooling Systems and Methods”, all of whichare incorporated by reference herein in their entirety.

FIELD OF THE INVENTION

The present invention generally relates to cooling systems and methodsand, in some embodiments, systems and methods for storing (e.g.,winterizing) and recharging adsorption cooling systems.

BACKGROUND OF THE INVENTION

Adsorption cooling systems using water as a refrigerant have beendeveloped for air conditioning and other cooling systems. Examples ofadsorption cooling systems are shown and described in U.S. PatentApplication Publication No. 2010/0043462, U.S. Pat. No. 7,836,723, andU.S. Pat. No. 5,813,248, which are hereby incorporated by reference intheir entirety.

BRIEF SUMMARY OF THE INVENTION

In one embodiment there is a cooling system comprising: at least oneevaporator containing a refrigerant; at least one adsorbent chamberfluidly coupled to the at least one evaporator and containing adsorbentconfigured to provide adsorption of vaporized refrigerant from the atleast one evaporator in a cooling mode and configured to providedesorption of the refrigerant to the at least one evaporator in arecharging mode; and a control system configured to control theadsorption and desorption of the refrigerant of the at least oneadsorbent chamber between the cooling modes and recharging modes duringa cooling cycle, wherein at the end of the cooling cycle the controlsystem is programmed to cease desorption of the refrigerant from the atleast one adsorbent chamber, allow adsorption of the vaporizedrefrigerant from the at least one evaporator and at the end of theadsorption cycle continue to maintain the at least one adsorbent chamberin an adsorbed state in a storage mode.

In one embodiment there is a cooling system comprising: at least oneevaporator containing a refrigerant; at least two adsorbent chambersfluidly coupled to the at least one evaporator and each containingadsorbent configured to provide adsorption of vaporized refrigerant fromthe at least one evaporator in a cooling mode and configured to providedesorption of the refrigerant to the at least one evaporator in arecharging mode; and a control system configured to control theadsorption and desorption of the refrigerant of the at least twoadsorbent chambers, the control system being programmed to alternate theat least two adsorbent chambers between the cooling modes and rechargingmodes to maintain substantially continuous adsorption of the vaporizedrefrigerant from the at least one evaporator during a cooling cycle,wherein at the end of the cooling cycle the control system is programmedto cease desorption of the refrigerant from the at least two adsorbentchambers, allow adsorption of the vaporized refrigerant from the atleast one evaporator and at the end of the adsorption cycle continue tomaintain the at least two adsorbent chambers in an adsorbed state in astorage mode.

In one embodiment, the cooling system further comprises a plurality ofvalves disposed between the at least one evaporator and the at least twoadsorbent chambers, the plurality of valves being controlled by thecontrol system. In one embodiment, the control system is programmed toopen the plurality of valves in the storage mode. In one embodiment thesystem further comprises a condenser fluidly coupled to the at least twoadsorbent chambers; and a water reservoir fluidly coupled between thecondenser and the at least one evaporator, wherein the at least oneevaporator includes a single evaporator. In one embodiment, therefrigerant is moved within the system only as a result of theadsorption in and desorption from the adsorbent and phase changes of therefrigerant. In one embodiment, the refrigerant is water. In oneembodiment, the adsorbent is zeolite. In one embodiment, the adsorbentis a material having a metal organic framework. In one embodiment, thecontrol system is programmable to automatically enter the storage modeat the end of the cooling cycle.

In one embodiment the cooling system further comprises an ambient airtemperature sensor, wherein the control system is programmed toautomatically enter the storage mode when the temperature sensor sensesa predetermined ambient air temperature. In one embodiment, the controlsystem is programmed to automatically enter into the recharging modeswhen the ambient air reaches a second predetermined ambient airtemperature. In one embodiment, the control system is remotelyprogrammable to enter the storage mode. In one embodiment, the coolingsystem further comprises at least one heat exchanger thermally coupledto the at least one evaporator and configured to exchange heat between aheat transfer medium and the at least one evaporator. In one embodiment,the cooling system further comprises at least one energy sourcethermally coupled to the at least two adsorbent chambers and configuredto heat the at least two adsorbent chambers during the recharging modes.In one embodiment, the at least one energy source includes exhaust froman engine of a vehicle. In one embodiment, the at least one energysource includes at least one heater, each heater thermally coupled to atleast one of the at least two adsorbent chambers, the control systembeing programmed to use the at least one heater to heat the at least twoadsorbent chambers during the recharging modes of the cooling cycle, thecontrol system being programmable to at least partially use the heatfrom the engine exhaust to heat the at least two adsorbent chamberscausing desorption of the refrigerant from the adsorbent.

In one embodiment, substantially all of the refrigerant is adsorbedwithin the adsorbent in the storage mode. In one embodiment, a volume ofthe refrigerant is substantially equal to or less than a totaladsorption capacity of the adsorbent. In one embodiment, the evaporatorincludes a thermally conductive liner. In one embodiment, there is amethod of operating a cooling system having at least one evaporatorcontaining a refrigerant and at least one adsorbent chamber containingadsorbent configured to provide adsorption of vaporized refrigerant fromthe at least one evaporator in a cooling mode and provide desorption ofthe refrigerant to the at least one evaporator in a recharging mode, themethod comprising: controlling the adsorption and desorption of therefrigerant of the at least one adsorbent chamber between the coolingmodes and recharging modes during a cooling cycle; ceasing desorption ofthe refrigerant from the at least one adsorbent chamber; allowingadsorption of the vaporized refrigerant from the at least oneevaporator; and maintaining the at least one adsorbent chamber in anadsorbed state at the end of the cooling cycle in a storage mode.

In one embodiment, the method further comprises using exhaust heat froman engine of a vehicle to heat the at least one adsorbent chamber andcause desorption of the refrigerant from the adsorbent following thestorage mode and before a subsequent cooling cycle. In one embodiment,the method further comprises automatically entering the storage modewhen a temperature sensor senses a predetermined ambient airtemperature. In one embodiment, the cooling system includes at least twoadsorbent chambers and further comprising: controlling the adsorptionand desorption of the refrigerant of the at least two adsorbent chambersbetween the cooling modes and recharging modes to maintain substantiallycontinuous adsorption of the vaporized refrigerant from the at least oneevaporator during a cooling cycle. In one embodiment, during the storagemode, the ambient temperature of the air is about or below the freezingpoint of the refrigerant. In one embodiment, substantially all of therefrigerant is adsorbed within the adsorbent in the storage mode.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The following detailed description of embodiments of the cooling systemsand methods will be better understood when read in conjunction with theappended drawings of exemplary embodiments. It should be understood,however, that the invention is not limited to the precise arrangementsand instrumentalities shown.

In the drawings:

FIG. 1 is a side cross sectional view of a cooling system in accordancewith an exemplary embodiment of the present invention;

FIG. 2 is a schematic diagram of the cooling system shown in FIG. 1;

FIG. 3 is a schematic diagram of a cooling system in accordance withanother exemplary embodiment of the present invention;

FIG. 4 is a flow chart of the operation of a cooling system inaccordance with an exemplary embodiment of the present invention;

FIG. 5 is a flow chart of the operation of a cooling system inaccordance with an exemplary embodiment of the present invention; and

FIG. 6 is a flow chart of the operation of a cooling system inaccordance with an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings in detail, there is shown in FIGS. 1-3 coolingsystems, generally designated 10 and 100, in accordance with exemplaryembodiments of the present invention. Exemplary uses of cooling systems10, 100 include air conditioning for homes, buildings and vehicles,potable liquid cooling systems (e.g., portable military or hiking watersystems), on demand cooling for beverage dispensing systems (e.g.,water, sports drinks, beer), industrial and environmental applications(e.g., cooling exhaust temperature of an incinerator), and military andathletic uniforms and protective apparel.

Referring to FIGS. 1 and 2, cooling system 10 includes a refrigerant 12contained within a refrigerant chamber 14. In one embodiment,refrigerant chamber 14 is fluidly coupled to an adsorbent chamber 16containing an adsorbent 18. Refrigerant chamber 14 is fluidly coupled toadsorbent chamber 16 via a fluid passageway 20 such as a pipe orconduit. In one embodiment, fluid passageway 20 includes one or morevalves 22 that control the fluid coupling between refrigerant chamber 14and adsorbent chamber 16. In one embodiment, refrigerant chamber 14 andadsorbent chamber 16 are contained within a common housing 28. In otherembodiments, housing 28 includes two or more parts. In one embodiment,refrigerant 12 is hermetically sealed within cooling system 10. In oneembodiment, adsorbent 18 is a material configured to adsorb and desorbrefrigerant 12. In one embodiment, adsorbent 18 is configured to provideadsorption of vaporized refrigerant 24 from refrigerant chamber 14 in acooling mode (illustrated in FIG. 1) and configured to providedesorption of refrigerant 12 back into refrigerant chamber 14 in arecharging mode. During the cooling mode, a heat transfer medium ormedia 26 is passed over, around and/or through refrigerant chamber 14 toform a heat exchanger coupling between heat transfer medium 26 andrefrigerant chamber 14.

Heat transfer medium 26 may be any suitable media to be cooled or usedto cool another medium. Heat transfer medium 26 may be the space ormedia to be cooled directly (e.g., heat transfer medium 26 in FIGS. 1and 2 is the water to be consumed). In other embodiments, heat transfermedium 26 may be used to extend the heat exchange with refrigerantchamber 14 to another area (e.g., a living room or sleeping space, seeFIG. 3) or media. In one embodiment, heat transfer medium 26 is air. Inone embodiment, heat transfer medium 26 is water. In one embodiment,heat transfer medium 26 includes glycol mixtures or other antifreezeagents.

As vaporized refrigerant 24 moves from refrigerant chamber 14 intoadsorbent chamber 16, the pressure within refrigerant chamber 14decreases reducing the boiling point of refrigerant 12 and causing it toevaporate, thereby decreasing the temperature of refrigerant chamber 14and pulling heat from heat transfer medium 26 such that exiting heattransfer medium 26 b is at a lower temperature than entering heattransfer medium 26 a. In order to reset or recharge cooling system 10and be ready for a subsequent cooling cycle, energy is applied toadsorbent chamber 16 to cause the adsorbed refrigerant 12 to desorb fromadsorbent 18 and back into refrigerant chamber 14. In one embodiment, aheater 30 having a fuel source 32 is used to apply heat to adsorbent 18in the recharging mode.

Refrigerant 12 may be cycled in a closed loop between the cooling andrecharging modes. In one embodiment, refrigerant 12 is water. In oneembodiment, refrigerant 12 is pure water. In one embodiment, refrigerant12 is substantially pure water. In one embodiment, refrigerant 12 iswater containing no additives. In other systems, water containingadjuvants may be desired as refrigerant 12. One example of usefuladjuvants is an anti-microbial (e.g., bacteriocidal or fungicidal)composition. In some embodiments, it is preferred that refrigerant 12does not contain materials which would interfere with operation ofcooling system 10 in its normal operation. Thus, in some embodiments,glycols and other antifreeze agents are generally to be excluded fromrefrigerant 12, at least in amounts effective for storing cooling system10 in ambient conditions around or below the freezing point ofrefrigerant 12.

In one embodiment, adsorbent 18 exhibits a high ability to adsorbrefrigerant 12 and to remain in an adsorbed state over practical lengthsof time, while maintaining physical and physicochemical form andfunction. Such materials may be useful when they exhibit a high abilityto adsorb water, efficient and effectively reversible desorption ofwater upon application of heat energy, and physical and physicochemicalstability during and following repeated adsorption and desorptioncycles.

In one embodiment, adsorbent 18 includes a desiccant material. In oneembodiment, adsorbent 18 is a desiccant. In one embodiment, adsorbent 18is zeolite. A zeolite may be described as, but without limitation,hydrous aluminum silicate in porous granules. Exemplary zeolites thatmay be used include analxime, chabazite, heulandite, natrolite,phillipsite and stilbite. In one embodiment, adsorbent 18 is any dryingagent that maintains its physical structure when substantially fullycontacted with water. In other embodiments, adsorbent 18 is anyadsorptive and/or absorptive material including but not limited todiatomaceous earth, activated alumina, silica gel, calciumaluminosilicate clay, molecular sieves (e.g., electrically chargedmolecular sieves), metal organic framework materials, activated carbon,and/or lithium chloride. In other embodiments, adsorbent 18 may be anelectrically chargeable and dischargeable material (e.g., a porous slabor particles of material such as a metal including aluminum, stainlesssteel and alloys thereof) such that electrical energy is used to controlthe electrical charge of the pores of the material to adsorb and desorbrefrigerant 12 from adsorbent 18.

A difficulty in water based adsorption cooling systems is the dangerfrom freezing of refrigerant 12 if exposed to cold ambient conditions.Should freezing of refrigerant 12 within cooling system 10 occur, splitpiping and/or damaged valves, seals, reservoirs and other components ofcooling system 10 could result causing cooling system 10 breakdown andpossibly other ancillary damage. To avoid these concerns, cooling system10 is winterized (e.g., safely stored for the duration of a winterseason or an otherwise cold period) by keeping refrigerant 12 adsorbedwithin adsorbent 18. In one embodiment, refrigerant 12 is adsorbedwithin adsorbent 18 prior to any freezing of refrigerant 12. Refrigerant12 may be adsorbed within adsorbent 18 to place cooling system 10 into astorage mode for any reason unrelated or in addition to freezingconcerns.

Refrigerant 12 may, in certain embodiments, be sealed within coolingsystem 10 such that draining of refrigerant 12 from cooling system 10 isimpractical or undesirable. Thus, were such closed cooling systems 10exposed to low temperatures, freezing of refrigerant 12 may occurleading to expansive damage to cooling system 10. In certainembodiments, the mass of refrigerant 12 stored within adsorbent 18 inthe storage mode does not freeze regardless of the ambient conditionssince refrigerant 12 is stored as individual molecules within the nanostructure of adsorbent 18. In such embodiments, refrigerant 12 withincooling system 10 in the storage mode is incapable of freezing in thestorage mode regardless of the ambient conditions.

In other embodiments, such as with absorptive materials as adsorbent 18for example, refrigerant 12 stored within adsorbent 18 may become coldand may chill substantially below the standard freezing point of waterbefore freezing or partially freezing. In use, when refrigerant 12 isstored within adsorbent 18, refrigerant 12 and the masses of adsorbent18 it is stored within does not expand as desorbed water begins toaround 4° Celsius. Storing refrigerant 12 within adsorbent 18 during thestorage mode reduces or avoids the damage to cooling system 10 thatmight otherwise result should desorbed refrigerant 12 expand uponfreezing. Cooling system 10 may therefore be safely stored in thestorage mode and subject to ambient conditions that would otherwisefreeze refrigerant 12 without having to drain refrigerant 12 fromcooling system 10.

It will be appreciated that in the normal operation of cooling system 10employing adsorptive cycles, refrigerant 12 is repeatedly adsorbed anddesorbed in adsorbent chamber 18. In one embodiment, the presentinvention permits such systems containing refrigerant 12 to be exposedto conditions under which refrigerant 12 would normally freeze, withrefrigerant 12 in place. In some embodiments, cooling system 10 isrecharged when winterization is no longer desired or required bydesorbing refrigerant 12 from adsorbent 18. In one embodiment,adsorption of refrigerant 12 is controlled through the use of valve 22.In one embodiment, desorption of refrigerant 12 is controlled by theapplication of external heat to adsorbent chamber 16. In one embodiment,cooling system 10 is manually entered into the storage mode. In otherembodiments, a control system 10 automatically enters cooling system 10into the storage mode.

In one embodiment, a method of operating cooling system 10 having atleast one evaporator or refrigerant chamber 14 containing refrigerant 12and at least one adsorbent chamber 16 containing adsorbent 18 configuredto provide adsorption of vaporized refrigerant 24 from the at least oneevaporator 14 in a cooling mode and provide desorption of refrigerant 12to the at least one evaporator 14 in a recharging mode, the methodincludes: controlling the adsorption and desorption of refrigerant 12 ofthe at least one adsorbent chamber 16 between the cooling modes andrecharging modes during a cooling cycle, ceasing desorption ofrefrigerant 12 from the at least one adsorbent chamber 16, allowingadsorption of vaporized refrigerant 24 from the at least one evaporator14, and maintaining the at least one adsorbent chamber 16 in an adsorbedstate at the end of the cooling cycle in a storage mode.

Cooling system 10 may be put into and kept in the storage mode, forexample, when the temperature of the ambient air is about or below thefreezing point of desorbed refrigerant 12. In one embodiment, thetemperature of the ambient air during the storage mode is approximately4° Celsius or lower. In one embodiment, valve 22 is opened to placecooling system 10 in the storage mode. In one embodiment, after theadsorbent chamber 16 is fully adsorbed, no heat is applied to adsorbentchamber 16 thereby keeping adsorbent chamber 16 and the cooling system10 in the storage mode. In one embodiment, cooling system 10 isautomatically put into the storage mode at the end of the cooling cycleregardless of the ambient temperature in the event the temperature ofthe ambient air unexpectedly drops to about or below the freezing pointof refrigerant 12. For example, if cooling system 10 is used during theday to keep drinking water cool, temperatures may drop expectedly orunexpectedly overnight when cooling system 10 is not in use. Also, ifcooling system 10 is used periodically, it may be days or months beforethe next cooling cycle and it may not be known if the temperature of theambient air will drop to about or below the freezing point ofrefrigerant 12. In mobile applications, cooling system 10 may be movedto or pass through a cold environment (e.g., in a truck driving from awarm coastal area through a cold mountainous area or a truck drivinginto a refrigerated storage building). In some embodiments, by keepingcooling system 10 in the storage mode after each cooling cycle, noaction is required if the temperature of the ambient drops to about orbelow the freezing point of refrigerant 12 whether or not thetemperature change was expected.

User may place cooling system 10 into the storage mode by adsorbingrefrigerant 12 into adsorbent 18 before refrigerant 12 can freeze. Inone embodiment, a user places cooling system 10 into the storage modemanually by leaving valve 22 open, or leaving valve 22 open for a periodof time at least long enough for adsorbent 18 to adsorb substantiallyall of refrigerant 12, and then ceasing to apply heat to adsorbentchamber 16 to desorb refrigerant 12 from adsorbent 18 such thatrefrigerant 12 remains in adsorbent 18. In other embodiments, coolingsystem 10 automatically or semi automatically enters into the storagemode with the use of an electronic control (see cooling system 100below). In one embodiment, cooling system 10 includes a temperaturesensor that is coupled to a control system configured to automaticallyenter the storage mode when the sensor senses a predetermined ambientair temperature (e.g., at or below the freezing temperature ofrefrigerant 12). In one embodiment cooling system 10 is configured toautomatically end the storage mode and desorb refrigerant 12 fromadsorbent chamber 16 when the temperature sensor senses a predeterminedambient air temperature (e.g., above the freezing temperature ofrefrigerant 12) or when cooling system 10 is turned on. In oneembodiment, the control system is configured to control valve 22 tocontrol the adsorption of refrigerant 12 into refrigerant chamber 14. Inone embodiment, the control system is configured to control the heatsource to control the desorption of refrigerant 12 from refrigerantchamber 14.

In one embodiment, a total volume of refrigerant 12 in liquid form issubstantially equal to or less than a total adsorption capacity ofadsorbent 18. In one embodiment, substantially all of refrigerant 12 isadsorbed within adsorbent 18 in the storage mode. In one embodiment,approximately 50% of refrigerant 12 is adsorbed within adsorbent 18 inthe storage mode. In one embodiment, approximately 60% of refrigerant 12is adsorbed within adsorbent 18 in the storage mode. In one embodiment,approximately 70% of refrigerant 12 is adsorbed within adsorbent 18 inthe storage mode. In one embodiment, approximately 80% of refrigerant 12is adsorbed within adsorbent 18 in the storage mode. In one embodiment,approximately 85% of refrigerant 12 is adsorbed within adsorbent 18 inthe storage mode. In one embodiment, approximately 90% of refrigerant 12is adsorbed within adsorbent 18 in the storage mode. In one embodiment,approximately 95% of refrigerant 12 is adsorbed within adsorbent 18 inthe storage mode. In one embodiment, approximately 96% of refrigerant 12is adsorbed within adsorbent 18 in the storage mode. In one embodiment,approximately 97% of refrigerant 12 is adsorbed within adsorbent 18 inthe storage mode. In one embodiment, approximately 98% of refrigerant 12is adsorbed within adsorbent 18 in the storage mode. In one embodiment,approximately 99% of refrigerant 12 is adsorbed within adsorbent 18 inthe storage mode. In one embodiment, approximately 99.5% of refrigerant12 is adsorbed within adsorbent 18 in the storage mode. In oneembodiment, approximately 99.6% of refrigerant 12 is adsorbed withinadsorbent 18 in the storage mode. In one embodiment, approximately 100%of refrigerant 12 is adsorbed within adsorbent 18 in the storage mode.In one embodiment, 100% of refrigerant 12 is adsorbed within adsorbent18 in the storage mode.

Referring to FIG. 3, in one exemplary embodiment, cooling system 100 isa substantially continuous cooling system. In one embodiment, coolingsystem 100 is a system used to cool a sleeping or passenger compartment52 of a truck while a driver sleeps as illustrated. However, coolingsystem 100 may be configured to cool any desirable space or media.

Cooling system 100 may provide continuous cooling by including two ormore adsorbent chambers 40, 42 that alternate between the cooling modesand recharging modes to maintain substantially continuous adsorption ofthe vaporized refrigerant 46 from the at least one evaporator 48 duringa cooling cycle. In one embodiment, a cooling cycle is continued so longas at least one adsorbent chamber 40, 42 is adsorbing refrigerant 46from evaporator 48. In one embodiment, heat transfer medium 44 iscoupled to evaporator 48 via a first heat exchanger 56. In oneembodiment, evaporator 48 absorbs heat from heat transfer medium 44 viafirst heat exchanger 56 and substantially maintains heat transfer medium44 below a desired temperature during the cooling cycle.

In one embodiment, heat transfer medium 44 is used to cool a desiredspace such as a space 52 through a second heat exchanger 58. In oneembodiment, space 52 is generally enclosed. In one embodiment, space 52is a room such as a sleeper compartment or passenger compartment of avehicle or a room of a house, or a liquid such as drinking water orbeer. In one embodiment, heat transfer medium 44 is moved between thefirst and second heat exchangers 56, 58 by a pump 50. In one embodiment,the second heat exchanger 58 includes a fan 54. In one embodiment, fan54 helps to distribute cooled air within space 52.

In one embodiment, cooling system 100 includes a reservoir 60. In oneembodiment, reservoir 60 is configured to contain refrigerant 12 inliquid form. In one embodiment, reservoir 60 is fluidly coupled toevaporator 48. In one embodiment, a valve 62 is disposed within andconfigured to control the fluid coupling between evaporator 48 andreservoir 60. In one embodiment, evaporator 48 is fluidly coupled tofirst adsorbent chamber 40. In one embodiment, a valve 64 is disposedwithin and configured to control the fluid coupling between evaporator48 and first adsorbent chamber 40. In one embodiment, evaporator 48 isfluidly coupled to second adsorbent chamber 42. In one embodiment avalve 66 is disposed within and configured to control the fluid couplingbetween evaporator 48 and second adsorbent chamber 42. In oneembodiment, a single evaporator 48 is fluidly coupled to two or moreadsorbent chambers 40, 42. In other embodiments, additional adsorbentchambers and evaporators may be provided in various configurations. Inone embodiment, condenser 72 is omitted. In other embodiments, condenser72, water reservoir 60 and evaporator 48 are combined into a singledevice (see FIGS. 1 and 2).

Referring to FIG. 5, because heat transfer medium 44 may eventuallyreach a temperature (e.g., approximately 50° F.) where refrigerant 12 inevaporator 48 begins to freeze potentially damaging the structuralintegrity (e.g., a hermetic seal) of evaporator 48, a temperature sensormay be provided within heat transfer medium 44 and/or evaporator 48 andone or more valves 62, 64, 66 may be closed or partially closed to slowor stop adsorption into adsorbent 18 and further cool refrigerant 12based on the sensed temperature. In other embodiments, one or morevalves 62, 64, 66 are opened to reduce the temperature of evaporator 48if heat transfer medium 44 exceeds a certain predetermined temperature.In one embodiment, valves 62, 64, 66 are binary. In other embodiments,valves 62, 64, 66 are adjustable to different amounts of opennessbetween ON and OFF. In one embodiment, control system 84 controls valves62, 64, 66. In one embodiment, control system 84 controls valves 62, 64,66 to maintain heat transfer medium 44 between a predeterminedtemperature range (e.g., approximately 52.5° F. to approximately 53.0°F.).

In some applications, it may be desirable to have evaporator go to lowerthan the approximate freezing temperature of refrigerant 12 (e.g., below0° C.). In such instances, rather than keeping a particular quantity ofrefrigerant 12 in evaporator 48 at all times, only the quantity requiredto be adsorbed into adsorbent 18 (e.g., a spray at a time) is fed intoevaporator 48. In one embodiment, valve 62 controls the amount ofrefrigerant 12 introduced into evaporator 48. In one embodiment, valve62 is controlled to feed refrigerant 12 into evaporator 48 at theapproximately at the same rate refrigerant 12 is leaving evaporator 48.In other embodiments, an injector, such as a sprayer, is used injectrefrigerant 12 into evaporator 48. Controlling the amount of refrigerant12 entering evaporator 48 may allow evaporator 48 to go to lower thanthe freezing temperature of refrigerant 12 with reduced or no risk offreezing damage because the quantity of refrigerant 12 introduced intoevaporator 48 at any given time is too low to cause damage.

In other embodiments, evaporator 48 may have a high thermalconductivity. For example, evaporator 48 may include a liner that isthermally conductive. Providing an evaporator 48 with a high thermalconductivity may help to more quickly transfer heat from the outside ofevaporator 48 to the inside of evaporator 48 to melt or prevent icedroplets from forming on the inside of evaporator 48.

In one embodiment, first adsorbent chamber 40 is fluidly coupled to acondenser 72. In one embodiment, second adsorbent chamber 40 is fluidlycoupled to condenser 72. In one embodiment, condenser 72 includes a fan74 configured to cool vaporized refrigerant 80 exiting first and secondadsorbent chambers 40, 42. In one embodiment, air is used to coolcondenser 72. In other embodiments, water or another liquid is used tocool condenser 72. In one embodiment, condenser 72 is fluidly coupled toreservoir 60. In one embodiment, condensed refrigerant 12 is transferredfrom condenser 72 into reservoir 60. In one embodiment, a valve 94 isdisposed within and configured to control the fluid coupling betweencondenser 72 and water reservoir 60. In one embodiment, a singlecondenser 72 is provided for two or more adsorbent chambers 40, 42. Inother embodiments, each adsorbent chamber 40, 42 is fluidly coupled toits own condenser 72.

In one embodiment, a first heater 68 is thermally coupled to firstadsorbent chamber 40. In one embodiment, first heater 68 is configuredto heat first adsorbent chamber 40 to a sufficient temperature to causerefrigerant within adsorbent 18 of first adsorbent chamber 40 to desorbfrom adsorbent 18 in the recharging mode. In one embodiment, firstadsorbent chamber 40 is thermally coupled to a fan 76 configured to coolfirst adsorbent chamber 40 following the desorbing or recharging modeand prior and/or during an adsorbing or cooling mode. In one embodiment,a second heater 70 is thermally coupled to second adsorbent chamber 42.In one embodiment, second heater 70 is configured to heat secondadsorbent chamber 42 to a sufficient temperature to cause refrigerantwithin adsorbent 18 of second adsorbent chamber 42 to desorb fromadsorbent 18 in the recharging mode. In one embodiment, second adsorbentchamber 42 is thermally coupled to a fan 78 configured to cool secondadsorbent chamber 42 following the desorbing or recharging mode andprior and/or during an adsorbing or cooling mode. In one embodiment,first and second heaters 68, 70 are powered by a fuel source 86. Fuelsource 86 may include any desirable fuel including natural gas, diesel,liquefied petroleum, heating oil, jet propellant, liquid propane, solarenergy, geothermal energy and/or a battery. In one embodiment, anadditional heat source 82, such as the exhaust from a combustion engine(e.g., the combustion engine of a vehicle using cooling system 100) orother waste heat, may be thermally coupled to one or more of the firstand second adsorbent chambers 40, 42 in the recharging modes anddiscussed further below. In some embodiments, a single fan is providedto cool first and second adsorbent chambers 40, 42. In some embodiments,a single heater is provided to heat first and second adsorbent chambers40, 42.

In one embodiment, refrigerant 12 is moved within cooling system 100only as a result of the adsorption in and desorption from adsorbent 18.In one embodiment, controlling one or more valves 62, 64, 66, 90, 92, 94and heaters 68, 70, 82 moves refrigerant 12 through cooling system 100without the assistance of one or more pumps. In other embodiments, oneor more pumps are provided to assist with moving refrigerant 12 withincooling system 100.

In one embodiment, cooling system 100 includes a control system 84. Inone embodiment, control system 100 includes one or more computers havingone or more processors and memory (e.g., one or more nonvolatile orvolatile storage devices). In some embodiments, memory or computerreadable storage medium of memory stores programs, modules and datastructures, or a subset thereof for a processor to control and run thevarious systems and methods disclosed herein. In one embodiment, anon-transitory computer readable storage medium having stored thereoncomputer-executable instructions which, when executed by a processor,perform one or more of the methods disclosed herein.

In one embodiment, control system 100 is electronically coupled to andconfigured to control the operation of one or more valves 62, 64, 66,90, 92, 94 to control the fluid coupling between various components ofcooling system 100. In one embodiment, control system 100 iselectronically coupled to and configured to control the operation of oneor more fans 54, 74, 76, 78 to cool various components of cooling system100. In one embodiment, control system 84 is electronically coupled toand configured to control the operation of heaters 68, 70, 82. In oneembodiment, control system 84 is powered by a power source 88. In oneembodiment, power source 88 is a battery. In one embodiment, powersource 88 is powered by fuel source 86. In one embodiment, power source88 is a thermoelectric generator.

In one embodiment, control system 100 is programmed to control theadsorption and desorption of refrigerant 12 of the adsorbent chambers40, 42 and alternate adsorbent chambers 40, 42 between the cooling modesand recharging modes to maintain substantially continuous adsorption ofvaporized refrigerant 46 from the evaporator 48 during a cooling cycle.In one embodiment, at the end of the cooling cycle control system 100 isprogrammed to cease desorption of refrigerant 80 from adsorbent chambers40, 42, allow adsorption of vaporized refrigerant 46 from evaporator 48and at the end of the adsorption cycle continue to maintain the at leasttwo adsorbent chambers in an adsorbed state in a storage mode.

Cooling system 100 may be entered into the storage mode in a variety ofways. FIG. 4 is a flow chart outlining three exemplary methods.Referring to FIG. 4, the “winterization configuration a” may be achievedby opening valves 1-5 corresponding to valves 62, 64, 66, 90, 92 shownin FIG. 3. The “winterization configuration b” may be achieved by fullyadsorbing cell a, corresponding to first adsorbent chamber 40 in FIG. 3and then subsequently fully adsorbing cell b, corresponding to secondadsorbent chamber 42 shown in FIG. 3. The “winterization configurationc” may be achieved by the same method as winterization configuration bwith the addition of applying additional heat to evaporator 48 toaccelerate adsorption.

Certain storage configurations may be faster than others but may usemore energy. Control system 84 and/or a user may therefore decide whichstorage configuration is optimal to use for a given situation. Referringto FIG. 6, for example, control system 84 may automatically enter intoone of a plurality of storage configurations based on how quickly theambient temperature is changing. In one embodiment, control system 84monitors the ambient temperature (e.g., using sensor 96 or receiveinformation from a weather report). When the ambient temperature fallsbelow a predetermined limit, control system 84 will record that currenttemperature. After a predetermined delay, control system 84 will recordwhat the ambient temperature changes to and compare what the differenceis to the initial recorded temperature. Control system 84 will thendecide, based on how quickly the temperature changed, whichwinterization configuration is the most optimal to use. For example, ifthe temperature is dropping slowly (e.g., less than a predeterminedvalue (“limit 1” in FIG. 6)) then control system 84 may utilize“winterization configuration a” by opening valves 1-5 corresponding tovalves 62, 64, 66, 90, 92 shown in FIG. 3. If the temperature isdropping more quickly (e.g., greater than a first predetermined value(“limit 1” in FIG. 6) and less than a second predetermined value (“limit2” in FIG. 6)) then control system 84 may utilize “winterizationconfiguration b” by fully adsorbing cell a, corresponding to firstadsorbent chamber 40 in FIG. 3 and then subsequently fully adsorbingcell b, corresponding to second adsorbent chamber 42 shown in FIG. 3. Ifthe temperature is dropping even more quickly (e.g., more than apredetermined value (“limit 2” in FIG. 6)) then control system 84 mayutilize “winterization configuration c” by the same method aswinterization configuration b with the addition of applying additionalheat to evaporator 48 to accelerate adsorption.

In certain embodiments, the user of cooling system 100 selects (e.g.,from a control panel or other control such as a cellular phone) certaincommands for control system 84 to execute. For example, user selects orprograms when the cooling cycle should start, when the cooling cycleshould end, whether to automatically recharge cooling system 100 whenwaste heat is available, and/or whether or not to enter the storage modeat the end of the cooling cycle.

Control system 84 may be programmed to automatically enter the storagemode. In one embodiment, control system 84 is programmed to enter thestorage mode at the end of the cooling cycle. In one embodiment, controlsystem 84 is programmed to enter the storage mode at the end of thecooling cycle unless the user selects otherwise. In one embodiment,control system 84 is programmed to enter the storage mode at apredetermined time (e.g., at 6:00 am or on October 1st) or as a resultof a predetermined condition (e.g., the engine of the vehicle has beenoff for over 12 hours or cooling system 100 has not been used for twoweeks), or at the end of each cooling cycle.

In one embodiment, control system 84 includes a sensor 96. In oneembodiment, sensor 96 is a temperature sensor. In one embodiment, sensor96 is a global positioning system (GPS). In one embodiment, sensor 96 isa pressure sensor. In one embodiment, sensor 96 is an altimeter. In oneembodiment, control system 84 automatically enters cooling system 100into the storage mode when sensor 96 senses a predetermined ambient airtemperature, air pressure, altitude and/or geographic location. Forexample, between cooling cycles if temperature sensor 96 senses apredetermined ambient air temperature (e.g., 10° Celsius), controlsystem 84 could open valves 64, 66 and/or apply heat to evaporator 48such that substantially all of refrigerant 12 is adsorbed in adsorbentchambers 40, 42. In one embodiment, control system 84 is programmed toautomatically recharge cooling system 100 and desorb refrigerant 12 fromat least one adsorbent chamber 40, 42 when temperature sensor 96 sensesa predetermined ambient air temperature. For example, when coolingsystem 100 is in the storage mode and the temperature sensor 96 senses apredetermined ambient air temperature (e.g., 15° Celsius), controlsystem 84 cause one or more heaters 68, 70, 82 to apply heat to one ormore adsorbent chambers 40, 42 so that cooling system 100 is rechargedand ready for a subsequent cooling cycle.

In one embodiment, control system 84 is programmed to automaticallyenter cooling system 100 into the storage mode based on actual orforecasted weather conditions. For example, the control system 84 mayreceive input from a weather report and if the temperature is orforecasted to be near or below a predetermined temperature value,control system 84 enters cooling system 100 into the storage modefollowing use of cooling system 100, or if not in use, automaticallyenter cooling system 100 into the storage mode at a predetermined time.

In one embodiment, control system 84 enters cooling system 100 into thestorage mode by opening one or more valves 64, 66. In one embodiment,eventually substantially all of refrigerant 12 is adsorbed intoadsorbent chambers 40, 42 even if heat transfer medium pump 50 is off.In one embodiment, control system 84 enters cooling system 100 into thestorage mode by keeping the adsorbent chambers 40, 42 adsorbed at theend of the cooling cycle. In one embodiment, the cooling system 100 isrun through a standard adsorption cycle, using heat from space 52 toheat heat transfer medium 44 and speed up the evaporation in theevaporator 48 and therefore speed up adsorption of refrigerant 12 intoadsorbent chambers 40, 42. In such an embodiment, the rechargingmechanism, the heaters 68, 70, 82 would be disengaged so that when eachadsorbent chamber 40, 42 is fully adsorbed, cooling system 100 would notgo into a desorbing mode. Cooling system 100 would remain the storagemode until one or more heaters 68, 70, 82 were used to desorb water fromadsorbent chambers 40, 42 to recharge cooling system 100.

In one embodiment, control system 84 enters cooling system 100 into thestorage mode by applying additional heat to evaporator 48. Additionalheat could be applied to evaporator 48 by one or more of heaters 68, 70used for recharging adsorbent chambers 40, 42 or additional heat source82 such as heat from a truck engine or other waste heat.

In one embodiment, control system 84 is coupled to a remote control,such a device connected to control system 84 through a wirelesscommunication system or through the internet, so that a user can inputcommands remotely (e.g., using a smart phone). In other embodiments, thecontrol system 84 is hard wired to a remote controlled device. In someembodiments, the user can adjust the operating and programmed parametersusing a remote controlled device. In one embodiment, actual ambientconditions or weather forecasts can be presented to the user (e.g.,using an application or app) and the user can select or program commandsfor entering cooling system 100 into a storage mode. For example, an appcan alert the user via an app on the user's smart phone that “thetemperature in Pittsburgh (current location) is predicted to be belowfreezing overnight. Do you want to enter the storage mode at the end ofthe cooling cycle?”. The user may be driving with the cooling system 100to a warmer climate where temperatures are predicted to be well abovefreeze and my therefore select “no” in response to the question.

In one embodiment, control system 84 is programmed to use additionalheat source 82 to exit the storage mode and desorb refrigerant from atleast one adsorbent chamber 40, 42. In one embodiment, control system 84is programmed to use additional heat source 82 to desorb refrigerantfrom at least one adsorbent chamber 40, 42 regardless of whether coolingsystem 100 is in the storage mode. For example, after a cooling cycle,cooling system 100 is stopped with one or both adsorbent chambers 40, 42in at least partially adsorbed state. Between cooling cycles, waste heatfrom additional heat source 82 may be available (e.g., the driver isdone sleeping in space 52, cooling system 100 is off, and driver beginsdriving his truck creating heat from the exhaust of the engine). Theheat from additional heat source 82 may be used to desorb refrigerantfrom one or both adsorbent chambers 40, 42 to rest cooling system 100for a subsequent cooling cycle and saving fuel from fuel source 86. Insome embodiments, the use of additional heat source 82 to desorb one ormore adsorbent chambers 40, 42 between cooling cycles may be turned off,either automatically or selectively, if cooling system 100 is to remainin the storage mode. In other embodiment, waste energy (e.g., energycaptured from braking of a vehicle) may be used to at least partiallyrecharge fuel and/or energy sources 86, 88.

It will be appreciated by those skilled in the art that changes could bemade to the exemplary embodiments shown and described above withoutdeparting from the broad inventive concepts thereof. It is understood,therefore, that this invention is not limited to the exemplaryembodiments shown and described, but it is intended to covermodifications within the spirit and scope of the present invention asdefined by the claims. For example, specific features of the exemplaryembodiments may or may not be part of the claimed invention and variousfeatures of the disclosed embodiments may be combined. Unlessspecifically set forth herein, the terms “a”, “an” and “the” are notlimited to one element but instead should be read as meaning “at leastone”.

It is to be understood that at least some of the figures anddescriptions of the invention have been simplified to focus on elementsthat are relevant for a clear understanding of the invention, whileeliminating, for purposes of clarity, other elements that those ofordinary skill in the art will appreciate may also comprise a portion ofthe invention. However, because such elements are well known in the art,and because they do not necessarily facilitate a better understanding ofthe invention, a description of such elements is not provided herein.

Further, to the extent that the method does not rely on the particularorder of steps set forth herein, the particular order of the stepsshould not be construed as limitation on the claims. The claims directedto the method of the present invention should not be limited to theperformance of their steps in the order written, and one skilled in theart can readily appreciate that the steps may be varied and still remainwithin the spirit and scope of the present invention.

We claim:
 1. A cooling system comprising: at least one evaporatorcontaining a refrigerant, the refrigerant comprised of water; at leasttwo adsorbent chambers fluidly coupled to the at least one evaporatorand each containing adsorbent configured to provide adsorption ofvaporized refrigerant from the at least one evaporator to cool therefrigerant in a cooling mode and configured to provide desorption ofthe refrigerant from the at least two adsorbent chambers in a rechargingmode; at least one energy source thermally coupled to the at least twoadsorbent chambers and configured to heat the at least two adsorbentchambers during the recharging modes, wherein the at least one energysource comprises exhaust from an engine of a vehicle; and a controlsystem configured to control the adsorption and desorption of therefrigerant of the at least two adsorbent chambers, wherein the controlsystem is programmed to alternate the at least two adsorbent chambersbetween the cooling modes and recharging modes to maintain substantiallycontinuous adsorption of the vaporized refrigerant from the at least oneevaporator during a cooling cycle, wherein at the end of the coolingcycle the control system is programmed to cease desorption of therefrigerant from the at least two adsorbent chambers, allow adsorptionof the vaporized refrigerant from the at least one evaporator and at theend of the adsorption cycle continue to maintain the at least twoadsorbent chambers in an adsorbed state in a storage mode.
 2. Thecooling system of claim 1 further comprising: a condenser fluidlycoupled to the at least two adsorbent chambers; and a water reservoirfluidly coupled between the condenser and the at least one evaporator,wherein the at least one evaporator includes a single evaporator.
 3. Thecooling system of claim 1, wherein the refrigerant is water.
 4. Thecooling system of claim 1, wherein the adsorbent is zeolite.
 5. Thecooling system of claim 1, wherein the adsorbent is a material having ametal organic framework.
 6. The cooling system of claim 1, wherein thecontrol system causes the at least two adsorbent chambers toautomatically enter the storage mode at the end of the cooling cycle. 7.The cooling system of claim 1 further comprising: an ambient airtemperature sensor, wherein the control system is programmed toautomatically enter the storage mode when the temperature sensor sensesa predetermined ambient air temperature.
 8. The cooling system of claim7, wherein the control system is programmed to automatically enter intothe recharging mode when the ambient air reaches a second predeterminedambient air temperature.
 9. The cooling system of claim 1, wherein thecontrol system is remotely programmable to cause the at least twoadsorbent chambers to enter the storage mode.
 10. The cooling system ofclaim 1 further comprising: at least one heat exchanger thermallycoupled to the at least one evaporator and configured to exchange heatbetween a heat transfer medium and the at least one evaporator.
 11. Thecooling system of claim 1, wherein the at least one energy sourceincludes at least one heater, each heater thermally coupled to at leastone of the at least two adsorbent chambers, the control system using theat least one heater to heat the at least two adsorbent chambers duringthe recharging mode of the cooling cycle, the control system at leastpartially using the heat from the engine exhaust to heat the at leasttwo adsorbent chambers causing desorption of the refrigerant from theadsorbent.
 12. The cooling system of any of claim 1, whereinsubstantially all of the refrigerant is adsorbed within the adsorbent inthe storage mode.
 13. The cooling system of claim 1, wherein a volume ofthe refrigerant is substantially equal to or less than a totaladsorption capacity of the adsorbent.
 14. The cooling system of claim 1,wherein the evaporator includes a thermally conductive liner.